The present invention concerns a liquid-resistant protective layer.
In particular it concerns a liquid-resistant protective layer basically formed of clay, in other words a clay mat.
Such clay mats are mainly used in water basins, canals and such as a sealing between the water and the ground; as a sealing between the water and the supporting structures in roof gardens, basements and such; as a sealing at waste dumping sites in order to avoid the penetration of rainwater and/or to prevent liquids from seeping through into the underlying ground; as a sealing in industrial installations such as tank parks, petrol stations, storage places, production units and such to prevent liquids from seeping through into the underlying ground, etc.
Such clay mats may De composed of a homogenous clay layer which is provided on either side with a coating, such as geofabric. This known embodiment is disadvantageous in that the clay can easily move between or come off the textile layers, such that micro-cracks or fissures may arise where liquid can seep through, and in that the clay can drop from between the textile layers at the edges when cutting such clay mats.
In order to remedy this disadvantage, a liquid-resistant layer has already been developed which consists of a compact layer made of a clay mass reinforced with fibres, which may or may not be provided with a coating.
Although such a liquid-resistant layer offers a solution to said disadvantage, such clay reinforced with fibres has another disadvantage, namely in that it has a negative effect on the self-sealing qualities in those places where such liquid-resistant layers overlap. Due to the good cohesion of reinforced clay, only little clay will migrate to the overlap, so that the clay sealing in the overlap zone is threatened.
This negative effect is often reinforced by the fact that the fibre density is usually greater at the surfaces of the layer containing the clay than in the middle part of this layer. Accordingly, on the one hand, there will be less clay at the surfaces and the migration of clay to the overlap will only be limited, or, on the other hand, a sort of wick effect is created, such that the ends of the fibres protrude from the layer concerned and thus form capillary passages in the overlap zone, where the water or such is in effect sucked through, like liquid through a wick.
Also, the present invention aims a liquid-resistant protective layer with which said disadvantage can be excluded.